An Indonesian man suspected of being al-Qaida’s chief operative in Southeast Asia appeared before a Guantanamo Bay review board on Thursday, making his first public appearance since his transfer to the detention facility in Cuba almost a decade ago.

Encep Nurjaman, better known as Hambali, was described by military officials as an “operational mastermind” of Jemaah Islamiah, the militant group that conducted the suicide bombing of a Bali nightclub in October 2002, killing more than 200 people in the region’s worst-ever terrorist attack.

The review board process was established by the Obama administration to conduct periodic assessments of the continued detention of prisoners at Guantanamo and give them a chance to argue for their release. The interagency boards are made up of senior national security officials.

Hambali, 52, was captured in Thailand a year after the Bali bombing and he passed through at least one CIA overseas prison before his transfer to Guantanamo. He is held there in the top-secret Camp 7 facility, along with a small group of high-profile detainees, including the men accused of organizing the Sept. 11, 2001, attacks.

Hambali appeared to hold influence over a number of his fellow detainees, promoting “violent jihad” during daily prayers and lectures

Flanked by U.S. military officials and a translator, Hambali sat quietly through the session, his eyes trained on a sheaf of papers as a statement was read by his representative, an unidentified U.S. military officer.

During the unclassified portions of the session watched by journalists via satellite link, Hambali made no acknowledgment of the officials around him. Dressed in a white T-shirt and wearing eyeglasses, he was neatly groomed and looked in good health.

Making the case for Hambali’s release, his military representative said that his client was respectful, energetic and “always smiling.” He said the Indonesian had used Rosetta Stone, an audio-learning course, to study English and Arabic, skills he now taught to other inmates.

The fate of most of the remaining 61 prisoners — many now described as ‘forever prisoners’

“Hambali has stated he has no ill will towards the U.S.,” the officer said in the statement, adding that his client wanted to live a peaceful life.

But in a separate character appraisal, another unidentified officer representing the U.S. government argued against release. He said Hambali appeared to hold influence over a number of his fellow detainees, promoting “violent jihad” during daily prayers and lectures.

The officer said Hambali was a key link between Jemaah Islamiah and al-Qaida. If Hambali is transferred out of Guantanamo, the officer said, U.S. officials believe he would look for ways to reconnect with his Indonesian and Malaysian terror network, or attract a new set of followers. His younger brother, Rusman Gunawan, is believed to have joined the Indonesia-based affiliate of the Islamic State, the officer said.

The hearing came as President Obama accelerates efforts to empty Guantanamo Bay, a facility he promised on his first day in office to close. To that end, the Pentagon said Monday that it had transferred 15 detainees from the prison to the United Arab Emirates, the largest release under the current president.

The fate of most of the remaining 61 prisoners – many now described as “forever prisoners” – will be harder to resolve.

Indonesian security officials say have said they want Hambali to stay in U.S. detention.

A 2014 Senate Intelligence Committee report said the CIA used “enhanced interrogation techniques” – often a euphemism for torture – on Hambali about a month into his CIA detention. According to the report, Hambali was told by an interrogator that he would never go to court: “We can never let the world know what I have done to you.”